I have a couple of questions about the experiment in this drama, but it can be summarised I guess as, can someone explain to me the purpose of the experiment and how it worked?
she leads me through moonlight only to burn me with the sun...
Which experiement, the starlight one?
shareyes.
she leads me through moonlight only to burn me with the sun...
I was confused about that too. I'm sure if you type it into google you'll get something (I don't have the energy at the mo to try and get my head around physics I don't understand) but from what I could understand, they were comparing the light from distant stars (from the same area of space) when the stars are behind the sun, and when they are not behind the sun. If the theory of relativity was correct, then the light from the stars would bend around the sun, so the images from the eclipse would be different from the images when the sun isn't in the way, which is why the stars didn't match up and there was a gap.
Wow that sounds rambling. Does that make sense?
Yea, that makes sense, thanks for the reply!
It's beginning to make sense for me now, I think I'll contemplate it further. I think I'm getting the relativity side of this, I'm missing something on the astronomy side to do with the position of the sun in the sky relative to the stars they were measuring, i.e. light might bend, but shouldn't it always be the same, i.e. it was always bending? if that makes sense.
Anyhow, looks like I need to go back to my physics for dummies book.
she leads me through moonlight only to burn me with the sun...
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I was at a complete loss as to what those three had in common, and I did A-level physics. Maybe it's something to do with Newton's laws, which I can't for the life of me remember?
shareThose three points are closely related
2. When they say that mercury behaves badly they mean that its orbit is not exactly described by Newtons laws. This is a sign that there could be a problem with Newtons laws. (it's called the Perihelion of mercury if you want to look it up)
3. According to relativity, space is warped or curved by massive bodies and as objects move through this curved space their path is changed and this effect is what we call gravity. (the apple and bread demonstration on the table cloth)
Matter tells space how to bend and space tells matter how to move.
1. Time fits into this by being considered as the fourth dimension of something called space-time. So it's actually space and time that are bent in a gravitational field. a clock on the surface of the earth ticks more slowly than a clock orbiting around the earth because the presence of the earth is bending time. Distances in time and space are also changed by travelling close to the speed of light, this is what Eddington learns from the Einstein book in the library,this is Special Relativity.
Einstein was able to explain the behaviour of mercury and his theory predicted that light should also be affected by gravity. Whereas in Newtons theory space and time are constant and light is unaffected by gravity. Eddington realised this difference could be tested by seeing if light was bent by the sun.
Hope that helps
Also, in the Eddington experiment, one of the photo plates was taken of the constellation at night with the sun on the otherside of the earth. The plate taken during the eclipse was of the constellation as seen behind the sun,i.e. with the light travelling past the sun. Thus, the light is only bent by the sun in the second plate.
shareBrilliantly well put!
shareAlso, in the Eddington experiment, one of the photo plates was taken of the constellation at night with the sun on the otherside of the earth. The plate taken during the eclipse was of the constellation as seen behind the sun,i.e. with the light travelling past the sun. Thus, the light is only bent by the sun in the second plate.Brilliantly well put indeed! - Thanks, I can see it now.
Only problem with the photographic plate comparison as portrayed in Einstein and Eddington is that Eddington is shown comparing *two* eclipse plates, the eclipsed Sun is on both. Of course there would have been no previous eclipse photographed in that exact position, and if there had been, the starlight would have been bent just the same as in the previous one. (As another poster said, you would wish to compare a pre-eclipse plate, and very carefully, Eddington's results were not quite so striking in reality, and have been disputed many times since, although Einstein has been proven right by may other experiments since.)
(It's also dramatic, but ridiculous, that Eddington should first check the results in front of a large invited audience, as the film implies, but that's down to dramatic licence, I guess.)
However, this is trivial compared with the big big scientific howler, which no-one on the net seems to have spotted yet. In the opening sequence, Eddington and Dyson are shown on the night before the eclipse fretting about the weather prospects the next day. The camera pulls back, and lo, there is a well-dramatic full moon visible through the thin cloud layers. Nice, but, of course, utterly impossible, because a total eclipse can only occur exactly on a new moon (two weeks later).
I wondered if this was a literary joke - Rider Haggard, in King Solomon's Mines (set in Africa too, of course), originally had a full moon, a total solar eclipse and another full moon appear on successive days. The author was embarrassed enough to change the solar eclipse to a lunar one in the second edition of the book:
http://books.google.co.uk/books?id=nyfIc8wkJzUC&pg=PA46&lpg=PA46&dq=rider+haggard+eclipse+full+moon+mistake&source=web&ots=YKdtt1-yuP&sig=aln2VsAj5i07WwDx0ukyWDQwMJE&hl=en&sa=X&oi=book_result&resnum=1&ct=result
I've got quite a few problems with the history in this film, but those two simple errors made me laugh. Nonetheless I enjoyed this as drama, even if it is scientific and historical fabulation.
On the subject of the ambiguity of the results, I've read since that Newton's theories actually already predicted bending of starlight, just by half the amount of Einstein's prediction.
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